why wouldn't they be? if it is a suspension of cells of photosynthesizing cells, they should make their food. At least at first, because if photosynthesis goes on without any way of exporting the trioses produced, the equilibrium of sugars will shift in favor of starch producing, the chloroplasts will turn to amyloplasts, end o story.

"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter